1. Field of the Invention
The field of this invention relates generally to positioning devices and specifically toward a positioning device for elevated laser beams.
2. Description of the Prior Art
Leveling devices are used primarily in the construction industry as an aid to framing carpenters, concrete form setters, tilt-up concrete crews, metal stud installers, and many other “mechanical” trades, as well as finish carpenters, cabinet installers, door hangers, glass installers and the like. Leveling devices are used to insure that the items being positioned or installed are in proper alignment in relation to the earth, and with other aspects of the construction. Traditionally bubble-vial levels are used for leveling in both horizontal and vertical directions. For leveling in a vertical direction, i.e., to make “plumb”, the definition of which is a true vertical position or alignment, plumb-bobs are also used. A plumb-bob is a weight, usually with a pointed tip on the bottom, which is suspended from a string and used as a vertical reference line, or plumb-line. Various laser tools project both level lines and plumb, i.e., vertical, lines that can be used to measure both level and plumb.
The use of lasers in vertical positioning is not new. However, there are significant disadvantages in the prior art that prohibit any practical usage. Of particular interest is U.S. Pat. No. 5,481,809 to Rooney. The Rooney device provides a means for producing a plumb laser beam offset from a wall a known distance. It operates specifically and solely with the use of a specially manufactured laser device contained within a conventional plumb bob housing. This device is limited, however, in that it is inherently insecure in any position except an inside corner. Additionally, it is inherently unstable and must be continually hand-held at height, as it is not provided with any means of inherently stable support or suspension. It is subject to disturbance by wind, and is not self dampening as other laser devices are currently available.
It is the primary object of the instant invention to provide an improved device that overcomes the shortcomings of the prior art. In particular, the instant invention provides a device to securely position a plumb laser beam in precise relation to the surfaces against which it bears. Additionally, the instant invention allows for use by only one person with the possibility of keeping both hands free. It is designed to hang or be suspended from walls and other surfaces by a variety of means.
The instant invention seeks to project a laser beam downwards that can establish a perfectly plumb line so that a wall (or any other objects placed at height) can be correctly positioned, i.e., made plumb or precisely positioned in relation to a fixed point, either above or (more commonly) below the object to be positioned. While the main concern with is with walls, to make them plumb, other horizontal construction components such as beams and mechanical components are often positioned from fixed layout points which are made on the floor (or ceiling) of a building. The instant invention is a more versatile and superior alternative to the use of bubble vial levels, and conventional plumb bobs.
Depending upon the capability of the laser instrument being used in the housing of the instant invention, the platform allows for the projection of at least three level beams at three angles: 0, 90 and 180 degrees. It can be used to position offset level laser beams, but is primarily designed to produce plumb laser beams, positioned in relation to a vertical surface.
Most laser instruments that project a plumb beam downwards also project a laser line upward. This upward line will be provided for in the design of the housing, that is it will be visible and usable when the laser is secured in the housing of the instant invention.
The device uniquely positions the laser by securely placing it at the top of the area of work and projecting a beam downwards at a known offset distance away from the surfaces against which it is bearing.